MLA

Pound, Ezra, 1885-1972. European Notes: typescript. Box 97, folder 4158. n.d.. https://collections.library.yale.edu/catalog/17122738.

APA, 6th edition

Pound, Ezra, 1885-1972. (["Box 97, folder 4158"])(n.d.)[European Notes: typescript]. https://collections.library.yale.edu/catalog/17122738.